A home security service may include a communication subsystem, such as a dial-up router, and a gateway for monitoring a CCD camera, an intrusion sensor and a fire sensor. Such a system can be controlled or monitored by a server system installed in a network center. A home automation service may have a home gateway to control the controller of another computer system, a television, a video player, lights or an air conditioner.
The home security service or home automation service preferably supports subscriber access to the home systems through a network center, using a portable telephone or a portable information terminal (such as a PDA or Personal Digital Assistant), to confirm the security system is operating properly or to remotely control home devices, such as lights. The subscriber's operation is accepted as the registration of a job with the server system of the network center. Registered jobs are transmitted by the server to the home gateway, which then performs the job or predetermined process. The jobs registered with the server system are not limited to requests from a subscriber, and other jobs, such as a request from a security service provider for a confirmation of the monitoring state or a regularly programmed process, can be registered.
The following two methods are used to notify a home gateway of jobs that are registered with a network center. The first is a pseudo push (polling) method. The second is a remote access method. According to the pseudo push method, the home gateway periodically issues an inquiry to the network center to determine whether a new job is present in the server. According to the remote access method, the home system router is configured in advance as a remote access server (RAS). A server in the network center initiates a call to the home router to directly notify the home router of a new job. For the remote access method, a job is normally initiated as soon as it is received in the network center.
Both of these methods have disadvantages. For the pseudo push method, every telephone call to the network system is initiated at the home system. The cost (if any) of the calls is charged directly to the subscriber. Since the calls are automatically made at regular intervals, any telephone costs are incurred regularly regardless whether the network center has any pending jobs for the home system. Further, according to the pseudo push method, the intervals at which the calls are made to the network center must be relatively short if job requests are to be relayed quickly to the home gateway, which is something subscribers expect to have happen. However, a shorter interval means more telephone calls and potentially higher subscriber telephone costs. Further, even if a short interval doesn't increase telephone costs, frequent queries to the network server will increase the load imposed on the server, which could lead to delays in transmitting job requests to subscriber home gateways.
If the remote access method is to be used, a home router must be capable of responding to an incoming call by initiating some action. Configuring such a router can be a complicated task. Further, to make sure only authorized persons call in job requests, security techniques such as use of passwords must be implemented and managed. Implementation and management of security requirements itself increases the costs of the services.
Also, since the network center initiates each telephone call to the home system, any costs of the call are incurred by the center. To avoid calling costs, a so-called free callback function might be implemented. Specifically, upon receipt of a new job request, the network center calls a home router, but terminates the call without completing the connection once the router recognizes the calling number as one being associated with the network center. The home router then automatically places a call back to the calling number to permit transfer of the job request from the network center to the home system. Any communication costs are incurred by the subscriber. However, in order to implement this callback function, a network center must have multiple outgoing lines and communication adapters since any line used to place a call to a home system must be dedicated to that call until the called home router calls back and the job request is transferred from the network center to the home system.
It is one object of the present invention to permit job requests to be transmitted quickly from a network center to a home system without an excessively large facility investment being required for the center. It is another object of the present invention to facilitate the configuration of a home router and to quickly transmit a new job request without the imposition of security requirements. It is an additional object of the invention to quickly transmit a new job request without a communication charge being incurred by the network center. It is a further object of the present invention to provide a job notification system that can adjust the load imposed on the server.